1. The Field of the Invention
The invention disclosed herein is in the field of anesthesia, more particularly the field of dental anesthesia. More particularly, the invention is in the field of nasal deliverable anesthesias that are sprayed or otherwise placed in the nasal cavity in order to numb the nerves associated with pain sensations generated by teeth and surrounding tissue within the maxillary dental arch.
2. The Relevant Technology
Most people fear going to the dentist. They equate visiting the dentist with pain. The most excruciating pain is typically caused by the drilling of cavities, root canal procedures, the pulling of teeth, crown and bridge work, and other procedures which disrupt, damage or otherwise put pressure on the pulp of a tooth and/or the surrounding maxillary bone and gingiva.
Various techniques have been employed to reduce the pain associated with the aforementioned dental procedures. The most common procedure to relieve or reduce dental pain is the application of a local anesthetic into the surrounding gingival tissue adjacent to the tooth. Alternatively, some dentists have found it useful to inject the anesthetic directly into the alveolar bone adjacent to the operative area. In many cases, application of the local anaesthetic by needle injection is itself very painful. The fear of needles is so great in some individuals that the injection can be more traumatic than the dental procedure itself. As between the upper and lower dental arches, most people believe that the pain associated with injecting a local anaesthetic to the upper dental arch is greater than with the lower dental arch.
Another source of fear is the possibility of failure of the anesthesia, which may result from incorrect placement of the anaesthetic. The duration of operative anesthesia may be unexpectedly short due to incorrect placement, the failure providing the correct dosage, or premature destruction of the anesthesia due to inflammation and associated low tissue pH. The proper dosage of anesthesia can vary greatly from one patient to the next, and can vary in the same patient due to biological variation, anxiety, fear, or infection in the area. The fear and anxiety associated with painful injections may actually deter some people from seeking dental work, even badly needed dental work required to relieve immediate pain and to correct serious acute or chronic conditions.
Complications can also occur with local injections. Locally, infections can occur and be transmitted through a contaminated needle. Improper placement of the needle can result in tearing or ripping of local tissue and nerves, as can delivering too large a volume of anesthetic to an area. Blood vessels can be lacerated when making regional blocks which may result in hematoma formation. In view of the foregoing, there has been a long-felt need to find alternatives to needle administered anesthesia.
One attempt at helping patients to overcome their fear of dental injections is the preliminary application of topical anesthetics in the form of gels, liquids, sprays, or patches to the gingival area where it is desired to insert the needle with the local anaesthetic. A topical anesthetic having a liquid or gel consistency and containing lidocaine, tetracaine, and adrenaline or epinephrine is described in U.S. Pat. No. 5,942,543 to Ernst. Another topical anesthetic gel composition, which purportedly aids in wound repair and hemostasis, is described in U.S. Pat. No. 5,563,153 to Mueller et al. The problem with topical anesthesia is at least two-fold: (1) patients still fear the needle and (2) the needle is still very painful once injected beyond the numbed gingival surface. In reality, topical anesthetics are only truly effective in relieving pain associated with superficial procedures such as suturing a laceration. Topical anesthetics do not effectively alleviate dental pain involving a tooth or the surrounding bone.
Yet another attempt at delivering a pain-free injection is disclosed in U.S. Pat. No. 5,180,371 to Spinello, which describes an aspirating hypodermic syringe capable of automatically injecting the dental anesthetic independent of squeezing by the dentists fingers. Spinello claims that the local anesthetic can be delivered even while the needle enters the tissue and then at different flow rates. The problem with the Spinello device is that it still involves an injection by a painful needle and, in view of the varying set flow rates intended to reduce pain, the length of time of the injection process is actually longer than manually performed injections. There is also the additional high cost of the device, both for the dentist and the patient. Attempts at improving the dental anesthetic pump are disclosed in U.S. Pat. No. 6,022,337 to Walter et al. and U.S. Pat. No. 5,368,572 to Shirota.
An attempt to alleviate a patient""s fear and anxiety of a needle by eliminating the needle altogether is described in U.S. Pat. Nos. 5,366,489 and 5,496,363 to Burgio. The Burgio patents claim to provide a needleless method for relieving pain by means of electrical impulses applied to local tissues in an attempt to temporarily block nerve sensations. This method is referred to as xe2x80x9ctranscutaneous electrical nerve stimulationxe2x80x9d, or xe2x80x9cTENSxe2x80x9d. In practice, the TENS method may actually provide enough blockage of sensation to allow for minor dental procedures, or to facilitate less painful injections for more involved dental procedures. However, this method has failed to save patients from having to endure painful injections when more intrusive and, hence, more painful, dental procedures are involved. Moreover, the TENS method has been associated with unpredictable results and has been generally ignored by the dental market. It is far more costly than simply providing topical anesthetics prior to dental injections.
One of the problems with anesthetizing teeth is the problem of accessing the nerves responsible for dental pain sensations. Because of the location of dental nerves, finding and numbing the nerves responsible for the pain sensation is not a very simple task. The same is not true for internal nasal tissues. Since internal nasal tissues include a large area of very thin mucous membrane tissue, topical anesthetics would be expected to be quite effective in immediately numbing pain for purposes of nasal surgery, such as the removal of polyps. This is in sharp contrast to teeth, which are completely immune to topical anesthetics applied thereto.
Accordingly, other interesting medical developments have been in the field of topical anesthetic sprays and aerosols used to deliver local anesthesia to the area of the larynx and respiratory system. For example, U.S. Pat. No. 5,571,071 to Shapiro discloses an improved laryngoscope blade having an attached anesthetic-containing reservoir for providing an anesthetic spray at one end of the blade. In addition, a fluid delivery means is included for providing anesthetic to other surfaces of the blade. U.S. Pat. No. 5,593,661 to Henry discloses the delivery of a selected dosage of lidocaine in an aerosolized form from a canister. The anesthetic so delivered is said to be useful in delivering anesthesia to a patient""s respiratory system, either directly or by way of an airway.
In view of the foregoing, it would be an improvement in the art to provide improved methods and systems for delivering a local anesthetic in connection with painful dental procedures, which was less painful to administer compared to conventional needle delivered anesthetics.
It would be an additional improvement in the art to provide methods and systems for delivering a local anesthetic in connection with painful dental procedures which eliminated the use of needle delivered anesthetics altogether, at least with respect to a portion of a patient""s teeth, particularly at least a portion of the patient""s upper dental arch, which is the most painful to anesthetize using a needle.
It would be a tremendous improvement in the art if such methods and systems for painlessly delivering a local anesthetic without the use of a needle also provided complete and total anesthetization of at least a portion of a patient""s teeth, particularly at least a portion of the patient""s upper dental arch, which is the most painful to anesthetize using a needle.
It would be an additional improvement in the art to provide methods and systems for painlessly anesthetizing a patient""s teeth without the use of a needle, which further allowed for the painless anesthetization of surrounding gingival tissues.
Such methods and systems for painlessly delivering a local anesthetic without the use of a needle in order to anesthetize at least a portion of patient""s teeth and surrounding tissues are disclosed and claimed herein.
The present invention relates to methods and systems for anesthetizing a patient""s teeth and surrounding palatal tissues within the maxillary dental arch by means of a nasal deliverable anaesthetic. Such methods and systems eliminate altogether the need for painful needle injected local anesthetics when preparing a patient for dental work on the maxillary, or upper, dental arch. By this means, patients will have less fear and anxiety when visiting a dentist and will experience greatly decreased pain associated with the application of the local anesthetic preparatory to carrying out the actual dental procedure. Moreover, because the nasal delivered anesthesia is total, complete and more easily administered compared to needle injected anesthetics, there is less danger of the anesthetic not taking effect or prematurely losing its anesthetizing effect compared to needle delivered anesthetics. The delivery of the anesthetics through topical absorption in the nasal cavity also eliminates the potential for accidental intervascular administration of anesthetics, as can occur during the administration of local, needle-delivered nerve blocks.
The nasal deliverable anesthetizing composition comprises one or more anesthetizing agents, such as lidocaine, tetracaine, or benzocaine, together with an appropriate liquid or gel carrier. The anesthetic composition may also include one or more vasoconstrictors in order to ensure more rapid uptake of the anesthetizing agent and also to help maintain the anesthetic localized in the desired area. The carrier may include any appropriate liquid or gel which yields an anesthetic composition having a desired rheology, pH, absorbability, and the like. Any other active agent or passive constituent may be added in order to provide any desired benefit to the patient, manufacturer, or person administering the anesthetic.
The nasal deliverable anesthetizing method may be employed through delivery of a single mixture of one or more an anesthetic agents, one or more vasoconstricting agents and associated carriers, or through delivery of multiple solutions. Ideally, the sequence of multiple solution delivery would be delivery of the vasoconstricting composition, followed by delivery of the anesthetic composition. A time period of one to ten minutes between administration of the two components may be beneficial in order to allow for maximum vasoconstriction and opening of the nasal canals prior to administration of the anesthetic composition.
The anesthetic composition may be introduced into a patient""s nasal cavity by means of any appropriate delivery system known in the art for delivering a nasal spray or nasal anesthetic. Examples include hand-held spray bottles, single dosage pump sprayers, pressurized aerosol canisters, pneumatically actuated sprayers, syringes or squeeze bottles equipped with tubular extensions, and the like. The delivery systems may be modified to provide for set dosages to be delivered. Atomizers or other means for providing a fine mist or spray are presently preferred, although the anaesthetic composition may certainly be applied as an non-atomized liquid, gel or even a solid, such as a powder. Delivery systems that better control the range or area of application may be better suited in anesthetizing only a portion of the patient""s teeth rather than the entire maxillary dental arch.
The inventor, who is an ear, nose and throat specialist by trade, found that, after anesthetizing a patient""s nasal cavity using a nasal delivered anesthesia preparatory to nasal procedures, the patient complained of extensive numbing of the upper dental arch, which the patient considered to be an undesirable side effect. Upon further analysis and inquiry, this unintended and undesired side effect of tooth numbing resulted from accidental application and absorption of the anesthetic in the region of the maxillary nerve and the pterygopalatine ganglion, a concentrated bundle of nerves located at the extreme rear upper end of the nasal cavity. The maxillary nerve is where the posterior, middle and anterior superior alveolar nerves collect, which are responsible for initially transmitting pain, temperature and pressure impulses generated by the nerves of the maxillary dentition and surrounding maxillary bone. After the impulses pass through the maxillary nerve and the main trunk of the trigeminal nerve, they are transmitted to the brain for processing and recognition.
The nasal deliverable anesthetizing compositions of the present invention are therefore believed to work by anesthetizing at least a portion of the branches of the maxillary nerve. Depending on the extent of anesthetization of the maxillary nerve and its associated branches, it is possible to numb the pain of part or all of the teeth and surrounding tissues of the maxillary arch. Moreover, introducing the nasal deliverable anesthesia into the left or right nasal cavities affects whether the left or right halves of the maxillary dental arch are anesthetized. This is fortunate, because it so happens that the teeth and surrounding tissue of the maxillary arch are the most painful and difficult parts of the mouth to properly anesthetize. By this means the dentist can more carefully control the location and extent of the anesthesia.
The surrounding facial gingival tissue (that which lies between the teeth and the lips) is not entirely anesthetized by the foregoing procedure, but may be readily and easily anesthetized by any desired means, such as by applying a topical anesthesia or a shallow and less painful injection of a local anesthesia.
The nasal deliverable anesthetic compositions of the present invention are unique in the field of dentistry. They offer the dentist, and more importantly the patient, a convenient and far less traumatizing method for obtaining profound anesthesia of the maxillary dentition, hard palate and soft palate. In particular, they offer complete elimination of patient fear of needle injections, as well as complete elimination of the pain associated with needle injections. The methods and systems of the present invention are far less technique-sensitive compared to needle injections. They eliminate, or at least reduce, the incidence of sharp biohazard wastes associated with used syringe needles. They eliminate the risk of accidental I.V. administration of local anesthetic/vasoconstricting solutions. They are completely effective in anesthetizing teeth with active infections that can render local, needle-delivered anesthetics ineffective due to inflammation and associated low pH. They provide partial or complete anesthesia of the maxillary dental arch without anesthetizing the lips. Finally, by alleviating the pain and fear associated with needle delivered anesthetics, they may encourage more people to seek help from a dentist in correcting health threatening dental maladies.
Accordingly, it is an object of the invention to provide improved methods and systems for delivering a local anesthetic in connection with painful dental procedures, which is less painful to administer compared to conventional needle delivered anesthetics.
It is an additional object and feature of the invention to provide methods and systems for delivering a local anesthetic in connection with painful dental procedures which eliminate the use of needle delivered anesthetics altogether, at least with respect to a portion of a patient""s teeth, particularly at least a portion of the patient""s maxillary dental arch, which is the most painful to anesthetize using a needle.
It is a further object and feature of the invention to provide methods and systems for painlessly anesthetizing a patient""s teeth without the use of a needle, which further allows for the painless anesthetization of surrounding gingival tissues.
These and other objects and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.